ISO 4773:2023 非破壊検査 — フェーズドアレイ技術を使用した超音波誘導波検査 | ページ 2

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives ).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents . ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html .

This document was prepared by Technical Committee ISO/TC 135, Non-destructive testing, Subcommittee SC 3, Ultrasonic testing.

Introduction

To improve guided-wave tests, coverage will be extended from above-ground to underground facilities, and the technology will transition from single-element use to multi-element phased-array technology. Noticeable advantages in using the phased-array ultrasonic guided-wave technique over the conventional single-element technique are improvements in the signal-to-noise ratio (SN ratio) and in the testing reliability in harsh environments like buried or coated pipelines.

A low signal-to-noise ratio in buried or coated pipe reduces the sensitivity and the range of conventional guided-wave testing. The phased-array guided-wave focusing method presented in this document can overcome this issue. Beam focusing and steering with the proper mode selection is a key benefit.

1 Scope

This document specifies a concept of application of phased-array guided-wave testing for various types of inaccessible structures, including buried pipelines.

Materials considered are carbon steel and stainless steel. This document does not include principles and criteria for underground facilities and the phased-array ultrasonic guided-wave testing scheme.

Furthermore, this document consists of an optimized process to draw reliable test results on inaccessible pipe cases. This document provides guidance on the use of phased-array guided-wave testing for various types of inaccessible structures, including buried pipelines made of carbon steel and stainless steel. The methodology outlined in this document includes an optimized process for achieving reliable test results on inaccessible pipe cases, with adjustments made to the beam pattern of the GW's focus location based on the defect type, location, and frequency. The process also takes into consideration the distribution diagram of the guided waves and the characteristics of the selected mode, with optimal focusing and steering achieved by adjusting the excitation time delay for each transducer based on the number of circumferential arrangement intervals of a given array probe.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 5577, ISO 18211 and ISO 23243 apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

Bibliography